SYSRC(8)                FreeBSD System Manager's Manual               SYSRC(8)

NAME
     sysrc - safely edit system rc files

SYNOPSIS
     sysrc [-cdDeEFhinNqvx] [-s name] [-f file] [-j jail | -R dir]
           name[[+|-]=value] ...
     sysrc [-cdDeEFhinNqvx] [-s name] [-f file] [-j jail | -R dir] -a | -A
     sysrc [-E] [-s name] [-f file] -l
     sysrc [-eEqv] -L [name ...]

DESCRIPTION
     The sysrc utility retrieves rc.conf(5) variables from the collection of
     system rc files and allows processes with appropriate privilege to change
     values in a safe and effective manner.

     The following options are available:

     -a       Dump a list of all non-default configuration variables.

     -A       Dump a list of all configuration variables (incl. defaults).

     -c       Check only.  For querying, return success if all requested
              variables are set (even if NULL), otherwise return error status.
              For assignments, return success if no changes are required,
              otherwise failure.  If verbose (see "-v") prints a message
              stating whether variables are set and/or changes are required.

     -d       Print a description of the given variable.

     -D       Show default value(s) only (this is the same as setting RC_CONFS
              to NULL or passing `-f' with a NULL file-argument).

     -e       Print query results as sh(1) compatible syntax (for example,
              `var=value').  Ignored if either `-n' or `-F' is specified.

     -E       When given `-l' or `-L' to list configuration files, only list
              those that exist.  When changing a setting, prefer to modify
              existing files.

     -f file  Operate on the specified file(s) instead of the files obtained
              by reading the `rc_conf_files' entry in the RC_DEFAULTS file.
              This option can be specified multiple times for additional
              files.

     -F       Show only the last rc.conf(5) file each directive is in.

     -h       Print a short usage message to stderr and exit.

     --help   Print a full usage statement to stderr and exit.

     -i       Ignore unknown variables.

     -j jail  The jid or name of the jail to operate within (overrides `-R
              dir'; requires jexec(8)).

     -l       List configuration files used at startup on stdout and exit.

     -L       List all configuration files including rc.conf.d entries on
              stdout and exit.  Can be combined with `-v' or `-e' to show
              service names.  sysrc exits with success if all named services
              are installed, failure otherwise.

     -n       Show only variable values, not their names.

     -N       Show only variable names, not their values.

     -q       Quiet.  Disable verbose and hide certain errors.  When combined
              with `-L' and one or more name arguments, provide only exit
              status and no output.

     -R dir   Operate within the root directory `dir' rather than `/'.

     -s name  If an rc.d script of name exists (in "/etc/rc.d" or
              local_startup directories), process its "rc.conf.d" entries as
              potential overrides to `rc_conf_files'.  See rc.subr(8) for
              additional information on "rc.conf.d".  Can be combined with
              `-l' to list configuration files used by service at startup.

     -v       Verbose.  Print the pathname of the specific rc.conf(5) file
              where the directive was found.

     --version
              Print version information to stdout and exit.

     -x       Remove variable(s) from specified file(s).

     This utility has a similar syntax to sysctl(8).  It shares the `-e' and
     `-n' options (detailed above) and also has the same `name[=value]' syntax
     for making queries/assignments.  In addition (but unlike sysctl(8)),
     `name+=value' is supported for adding items to values (see APPENDING
     VALUES) and `name-=value' is supported for removing items from values
     (see SUBTRACTING VALUES).

     However, while sysctl(8) serves to query/modify MIBs in the entrant
     kernel, sysrc instead works on values in the system rc.conf(5)
     configuration files.

     The list of system configuration files is configured in the file
     `/etc/defaults/rc.conf' within the variable `rc_conf_files', which by-
     default contains a space-separated list of pathnames.  On all FreeBSD
     systems, this defaults to the value "/etc/rc.conf /etc/rc.conf.local".
     Each pathname is sourced in-order upon startup.  It is in the same
     fashion that sysrc sources the configuration files before returning the
     value of the given variable.

     When supplied a variable name, sysrc will return the value of the
     variable.  If the variable does not appear in any of the configured
     `rc_conf_files', an error is printed and error status is returned.

     When changing values of a given variable, it does not matter if the
     variable appears in any of the `rc_conf_files' or not.  If the variable
     does not appear in any of the files, it is appended to the end of the
     first pathname in the `rc_conf_files' variable.  Otherwise, sysrc will
     replace only the last-occurrence in the last-file found to contain the
     variable.  This gets the value to take effect next boot without heavily
     modifying these integral files (yet taking care not to allow the file to
     grow unwieldy should sysrc be called repeatedly).

APPENDING VALUES
     When using the `key+=value' syntax to add items to existing values, the
     first character of the value is taken as the delimiter separating items
     (usually " " or ",").  For example, in the following statement:

           sysrc cloned_interfaces+=" gif0"

     the first character is a space, informing sysrc that existing values are
     to be considered separated by whitespace.  If `gif0' is not found in the
     existing value for cloned_interfaces, it is added (with delimiter only if
     existing value is non-NULL).

     For convenience, if the first character is alpha-numeric (letters A-Z,
     a-z, or numbers 0-9), dot (.), or slash (/), sysrc uses the default
     setting of whitespace as separator.  For example, the above and below
     statements are equivalent since "gif0" starts with an alpha-numeric
     character (the letter g):

           sysrc cloned_interfaces+=gif0

     Take the following sequence for example:

           sysrc cloned_interfaces= # start with NULL

           sysrc cloned_interfaces+=gif0
                 # NULL -> `gif0' (NB: no preceding delimiter)

           sysrc cloned_interfaces+=gif0 # no change

           sysrc cloned_interfaces+="tun0 gif0"
                 # `gif0' -> `gif0 tun0' (NB: no duplication)

     sysrc prevents the same value from being added if already there.

SUBTRACTING VALUES
     When using the `key-=value' syntax to remove items from existing values,
     the first character of the value is taken as the delimiter separating
     items (usually " " or ",").  For example, in the following statement:

           cloned_interfaces-=" gif0"

     the first character is a space, informing sysrc that existing values are
     to be considered separated by whitespace.  If `gif0' is found in the
     existing value for cloned_interfaces, it is removed (extra delimiters
     removed).

     For convenience, if the first character is alpha-numeric (letters A-Z,
     a-z, or numbers 0-9), dot (.), or slash (/), sysrc uses the default
     setting of whitespace as separator.  For example, the above and below
     statements are equivalent since "gif0" starts with an alpha-numeric
     character (the letter g):

           sysrc cloned_interfaces-=gif0

     Take the following sequence for example:

           sysrc foo="bar baz" # start

           sysrc foo-=bar # `bar baz' -> `baz'

           sysrc foo-=baz # `baz' -> NULL

     sysrc removes all occurrences of all items provided and collapses extra
     delimiters between items.

ENVIRONMENT
     The following environment variables are referenced by sysrc:

     RC_CONFS         Override default `rc_conf_files' (even if set to NULL).

     RC_DEFAULTS      Location of `/etc/defaults/rc.conf' file.

DEPENDENCIES
     The following standard commands are required by sysrc:

     awk(1), cat(1), chmod(1), env(1), grep(1), mktemp(1), mv(1), rm(1),
     sh(1), stat(1), tail(1), chown(8), jls(8), and jexec(8).

FILES
     /etc/defaults/rc.conf
     /etc/rc.conf
     /etc/rc.conf.local
     /etc/rc.conf.d/name
     /etc/rc.conf.d/name/*
     /usr/local/etc/rc.conf.d/name
     /usr/local/etc/rc.conf.d/name/*

EXAMPLES
     Below are some simple examples of how sysrc can be used to query certain
     values from the rc.conf(5) collection of system configuration files:

     sysrc sshd_enable
           returns the value of $sshd_enable, usually YES or NO.

     sysrc defaultrouter
           returns IP address of default router (if configured).

     Working on other files, such as crontab(5):

     sysrc -f /etc/crontab MAILTO
           returns the value of the MAILTO setting (if configured).

     Appending to existing values:

     sysrc cloned_interfaces+=gif0
           appends "gif0" to $cloned_interfaces (see APPENDING VALUES).

     sysrc cloned_interfaces-=gif0
           removes "gif0" from $cloned_interfaces (see SUBTRACTING VALUES).

     In addition to the above syntax, sysrc also supports inline sh(1)
     PARAMETER expansion for changing the way values are reported, shown
     below:

     sysrc 'hostname%%.*'
           returns $hostname up to (but not including) first `.'.

     sysrc 'network_interfaces%%[$IFS]*'
           returns first word of $network_interfaces.

     sysrc 'ntpdate_flags##*[$IFS]'
           returns last word of $ntpdate_flags (time server address).

     sysrc usbd_flags-"default"
           returns $usbd_flags or default if unset or NULL.

     sysrc cloned_interfaces+"alternate"
           returns alternate if $cloned_interfaces is set.

SEE ALSO
     rc.conf(5), jail(8), jexec(8), jls(8), rc(8), rc.subr(8), sysctl(8)

HISTORY
     A sysrc utility first appeared in FreeBSD 9.2.

AUTHORS
     Devin Teske <dteske@FreeBSD.org>

THANKS TO
     Brandon Gooch, Enji Cooper, Julian Elischer, Pawel Jakub Dawidek, Cyrille
     Lefevre, Ross West, Stefan Esser, Marco Steinbach, Jilles Tjoelker, Allan
     Jude, and Lars Engels for suggestions, help, and testing.

FreeBSD 13.1-RELEASE-p6        February 26, 2019       FreeBSD 13.1-RELEASE-p6